5 years after BP spill, drillers push into riskier depths

Cain Burdeau, Associated Press

Published 8:00 pm, Sunday, April 19, 2015

Photo: Gerald Herbert

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FILE - In this April 21, 2010 file photo by Gerald Herbert, the Deepwater Horizon oil rig burns in the Gulf of Mexico. Rig fires happen with some regularity, but when word came that the rig was listing badly after an explosion the night before, New Orleans-based Gerald Herbert raced to a small airport and grabbed the first helicopter pilot he could find. Together with a photographer from the Times-Picayune newspaper, the three headed out in a four-seat helicopter with only enough fuel to get to the site and shoot for a few minutes. less

FILE - In this April 21, 2010 file photo by Gerald Herbert, the Deepwater Horizon oil rig burns in the Gulf of Mexico. Rig fires happen with some regularity, but when word came that the rig was listing badly ... more

Photo: Gerald Herbert

5 years after BP spill, drillers push into riskier depths

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ON THE GULF OF MEXICO — Five years after the nation’s worst offshore oil spill, the industry is working on drilling even further into the risky depths beneath the Gulf of Mexico to tap massive deposits once thought unreachable. Opening this new frontier, miles below the bottom of the Gulf, requires engineering feats far beyond those used at BP’s much shallower Macondo well.

But critics say energy companies haven’t developed the corresponding safety measures to prevent another disaster or contain one if it happens — a sign, environmentalists say, that the lessons of BP’s spill were short-lived.

These new depths and larger reservoirs could exacerbate a blowout like what happened at the Macondo well. Hundreds of thousands of barrels of oil could spill each day, and the response would be slowed as the equipment to deal with it — skimmers, boom, submarines, containment stacks — is shipped 100 miles or more from shore.

Since the Macondo disaster, which sent at least 134 million gallons spewing into the Gulf five years ago Monday, federal agencies have approved about two dozen next-generation, ultra-deep wells.

The number of deepwater drilling rigs has increased, too, from 35 at the time of the Macondo blowout to 48 last month, according to data from IHS Energy, a Houston company that collects industry statistics.

Department of Interior officials overseeing offshore drilling did not provide data on these wells and accompanying exploration and drilling plans, information that The Associated Press requested last month.

But a review of offshore well data by the AP shows the average ocean depth of all wells started since 2010 has increased to 1,757 feet, 40 percent deeper than the average well drilled in the five years before that.

And that’s just the depth of the water.

Drillers are exploring a “golden zone” of oil and natural gas that lies roughly 20,000 feet beneath the sea floor, through a 10,000-foot thick layer of prehistoric salt — far deeper than BP’s Macondo well, which was considered so tricky at the time that a rig worker killed in the blowout once described it to his wife as “the well from hell.”

Geophysicists estimate oil companies can unleash Saudi Arabian-like gushers at these unprecedented depths from fields capable of yielding up to 300,000 barrels of oil a day.

Temperatures and pressures — the conditions that make drilling so risky — get more intense the deeper you go. And the ancient salt layer brings extra wild cards.

Technology now allows engineers to see the huge reservoirs beneath the previously opaque salt, but the layer is still harder to see through than rock. And it’s prone to hiding pockets of oil and gas that raise the potential for a blowout.

“It’s not rocket science,” said Matthew Franchek, director of the University of Houston’s subsea engineering graduate program. “Oh, no, it’s much, much more complicated.”